CN112113241A

CN112113241A - Rectifying grid of stamping combustion chamber

Info

Publication number: CN112113241A
Application number: CN202010990129.7A
Authority: CN
Inventors: 何陈; 邓远灏; 康松; 张飞; 周雄; 姜军; 钟世林
Original assignee: AECC Sichuan Gas Turbine Research Institute
Current assignee: AECC Sichuan Gas Turbine Research Institute
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2020-12-22
Anticipated expiration: 2040-09-18
Also published as: CN112113241B

Abstract

The invention belongs to the technical field of aero-engines, and particularly relates to a rectifying grid of a stamping combustion chamber, which comprises a front grid and a rear grid; the front grille is arranged at a diffuser inlet of the stamping combustion chamber and used for buffering high-speed airflow at the diffuser inlet and guiding part of the buffered high-speed airflow to the central area of the diffuser; the back grating is arranged at the outlet of the diffuser of the stamping combustion chamber and used for buffering the air flow in the central area of the diffuser and uniformly diffusing the buffered air flow in the central area of the diffuser outwards along the central area. According to the design scheme of the rectification grid of the stamping combustion chamber, the front rectification grid and the rear rectification grid are arranged at the inlet and the outlet of the diffuser for combined rectification, the defects of the rectification grid of the existing stamping combustion chamber are overcome, the rectification capacity of the rectification grid can be obviously improved compared with that of the traditional single-layer grid, the unevenness of distorted air flow is reduced, and the total pressure loss of the grid can be effectively reduced.

Description

Rectifying grid of stamping combustion chamber

Technical Field

The invention belongs to the technical field of aero-engines, and particularly relates to a rectifying grid of a stamping combustion chamber.

Background

Factors such as interaction of shock waves and boundary layers in an air inlet channel, attack angles of aircrafts and the like can cause flow separation and uneven flow field distribution at an inlet of the stamping combustion chamber. The inlet airflow of the stamping combustion chamber is uneven, so that the oil-gas distribution in the stamping combustion chamber deviates from the oil-gas ratio favorable for efficient combustion, the combustion efficiency is reduced, the stable combustion range is narrowed, and meanwhile, the possibility of large-area combustion in the edge area exists, so that the heat protection of the heat shield is difficult; the combustor inlet flow splits so that combustion may occur upstream of the stabilizer, which may cause "sparking" of the lance and flame holder pull rod, etc., with the potential for localized ablation. In order to improve the flow field quality of the combustion chamber of the ramjet engine and reduce the nonuniformity of the pressure and the speed distribution of the inlet flow field of the combustion chamber of the ramjet engine, a part of a rectifying grid is required to be arranged in the ramjet combustion chamber.

The rectifying grating is arranged in a diffuser of the stamping combustion chamber, the existing rectifying grating is in the form of a single-layer flat plate or a conical plate with single-layer uniformly distributed round/square grid holes, and airflow in a high-speed area is forced to flow to a low-speed area through the blocking effect of the grid holes. In this way, the straightening grids are generally required to have a large blockage ratio to have a good straightening effect, but an excessively large blockage ratio causes a great total pressure loss and has a great influence on the performance of the stamping combustion chamber.

Disclosure of Invention

In order to solve the technical problems in the prior art, a rectification grid of the stamping combustion chamber is provided, and a design scheme of the rectification grid of the stamping combustion chamber for combining and rectifying two rectification grids at the front and the back is arranged at the inlet and the outlet of a diffuser. The shortcoming of the rectification grid of the existing stamping combustion chamber is overcome, the mode of combining and rectifying the front and the back rectification grids at the inlet and the outlet of the diffuser is used, the rectification capacity of the single-layer grid can be obviously improved compared with the traditional single-layer grid, and the distortion airflow unevenness is reduced. Meanwhile, the positions of the front and rear grids are staggered, so that the blocking area is small, and the total pressure loss of the grids can be effectively reduced. The novel double-grid combined rectification scheme can obviously improve the working performance of the rectification grids.

In order to achieve the technical purpose, the invention adopts the following specific technical scheme:

a stamped combustion chamber rectifying grid comprises a front grid and a rear grid; the front grille is arranged at a diffuser inlet of the stamping combustion chamber and used for buffering high-speed airflow at the diffuser inlet and guiding part of the buffered high-speed airflow to the central area of the diffuser;

the back grating is arranged at the outlet of the diffuser of the stamping combustion chamber and used for buffering the air flow in the central area of the diffuser and uniformly diffusing the buffered air flow in the central area of the diffuser outwards along the central area.

Furthermore, the front grating is in a circular truncated cone curved surface shape, the radius of the bottom is equal to the radius of the inlet of the diffuser, and the radius of the top is 0.7-0.8 times of the radius of the bottom; the front grille is fixed at the inlet of the diffuser through the bottom of the front grille.

Furthermore, the grid holes in the front grid are uniformly distributed and are circular grid holes, and the radius of the grid holes is 0.08-0.09 time of the radius of the bottom of the front grid.

Further, the axial distance between the bottom of the front grille and the top of the front grille is 0.2-0.3 times of the radius of the bottom of the front grille.

Furthermore, the top of the rear grating is spherical, the main body of the rear grating is a circular truncated cone curved surface, the top of the rear grating faces the front grating, and the radius of the bottom of the rear grating is larger than that of the top of the front grating; the rear grating and the front grating are coaxially arranged.

Furthermore, the grid holes on the rear grid are uniformly distributed and are circular grid holes; the radius of the circular grid holes is equal to that of the grid holes of the front grid.

Further, the axial distance between the bottom of the rear grille and the top of the rear grille is 0.2-0.3 times of the radius of the bottom of the rear grille.

Further, the radius of the top spherical surface of the rear grating is 0.4-0.6 times of the radius of the bottom spherical surface of the rear grating.

By adopting the technical scheme, the invention can bring the following beneficial effects:

the invention provides a design scheme of a rectification grating of a stamping combustion chamber, wherein the rectification grating is combined and rectified by a front rectification grating and a rear rectification grating at the inlet and the outlet of a diffuser. The airflow reducing unevenness capacity of the rectifying grating of the stamping combustion chamber can be effectively improved, the total pressure recovery coefficient of the rectifying grating can be improved, and the normal work of the stamping combustion chamber under the inlet airflow distortion condition can be guaranteed at the cost of lower total pressure loss.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a ramjet combustor fairing installed in a ramjet combustor in an embodiment of the present invention;

FIG. 2 is a schematic view of a stamped combustor flow straightener in an embodiment of the present invention;

FIG. 3 is a left side view of a front grill in an embodiment of the present invention;

FIG. 4 is a front view of a front grill in an embodiment of the present invention;

FIG. 5 is a left side view of the rear grill in an embodiment of the present invention;

fig. 6 is a front view of a rear grill in an embodiment of the present invention.

Detailed Description

The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

The embodiments of the present disclosure are described below with specific examples, and other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from the disclosure in the specification. It is to be understood that the described embodiments are merely illustrative of some, and not restrictive, of the embodiments of the disclosure. The disclosure may be embodied or carried out in various other specific embodiments, and various modifications and changes may be made in the details within the description without departing from the spirit of the disclosure. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

It is noted that various aspects of the embodiments are described below within the scope of the appended claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the disclosure, one skilled in the art should appreciate that one aspect described herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. Additionally, such an apparatus may be implemented and/or such a method may be practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present disclosure, and the drawings only show the components related to the present disclosure rather than the number, shape and size of the components in actual implementation, and the type, amount and ratio of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

The disclosed embodiment provides a stamped combustion chamber rectification grid, as shown in fig. 1 or fig. 2, comprising a front grid 1 and a rear grid 2; the front grille 1 is arranged at an inlet of a diffuser 3 of the stamping combustion chamber and used for buffering high-speed airflow at the inlet of the diffuser 3 and guiding part of the buffered high-speed airflow to the central area of the diffuser 3;

the back grating 2 is arranged at the outlet of the diffuser 3 of the stamping combustion chamber and is used for buffering the air flow in the central area of the diffuser 3 and uniformly diffusing the buffered air flow in the central area of the diffuser 3 outwards along the central area.

In the embodiment, the front grille 1 is in a circular truncated cone curved surface shape, the radius of the bottom is equal to the radius of the inlet of the diffuser 3, and the radius of the top is 0.7-0.8 times of the radius of the bottom; the front grill 1 is fixed to the inlet of the diffuser 3 through the bottom thereof. The specific dimensions are shown in fig. 3 or fig. 4.

In this embodiment, the grid holes on the front grid 1 are uniformly distributed, are circular grid holes, and have a radius 0.08-0.09 times of the radius of the bottom of the front grid 1. The specific dimensions are shown in fig. 3 or fig. 4.

In the embodiment, the axial distance between the bottom of the front grille 1 and the top thereof is 0.2-0.3 times of the radius of the bottom thereof. The specific dimensions are shown in fig. 3 or fig. 4.

In the present embodiment, as shown in fig. 1 or fig. 2, the top of the rear grille 2 is spherical, the main body is truncated cone-shaped, the top faces the front grille 1, and the bottom radius is greater than the top radius of the front grille 1; the rear grill 2 is disposed coaxially with the front grill 1.

In the embodiment, the grid holes on the rear grid 2 are uniformly distributed and are circular grid holes; the radius of the circular grating holes is equal to that of the grating holes of the front grating 1. The specific dimensions are shown in fig. 5 or fig. 6.

In the embodiment, the axial distance between the bottom of the rear grille 2 and the top thereof is 0.2-0.3 times of the radius of the bottom thereof. The specific dimensions are shown in fig. 5 or fig. 6.

In the present embodiment, the radius of the top spherical surface of the rear grill 2 is 0.4 to 0.6 times the radius of the bottom spherical surface thereof. The specific dimensions are shown in fig. 5 or fig. 6.

In this embodiment, under the general condition, the air current of punching press combustion chamber import department has the inhomogeneities, and its high-speed air current concentrates near being close to preceding grid 1 bottom, and the ratio of preceding grid 1 top radius and bottom radius is 0.7 ~ 0.8, can be better play the buffering air current effect, has avoided too big jam simultaneously, plays the effect that reduces total pressure loss.

The radius of the circular grid holes is 0.08-0.09 times of the radius of the bottom of the front grid 1, so that the buffering effect can be better played, and meanwhile, local unevenness caused by the grid holes is avoided.

The axial distance between the bottom of the front grid 1 and the top of the front grid is 0.2-0.3 times of the radius of the bottom of the front grid, so that the drainage effect can be better played, and the total pressure loss of airflow is reduced.

The axial distance between the bottom of the rear grating 2 and the top of the rear grating is 0.2-0.3 times of the radius of the bottom of the rear grating, and the spherical radius of the top of the rear grating 2 is 0.4-0.6 times of the radius of the bottom of the rear grating, so that the diffusion effect can be better played, and the total pressure loss of the airflow is reduced.

In this embodiment, as shown in fig. 1, the diffuser 3 is a straight-wall conical channel, the inlet of the diffuser is connected to the incoming flow channel 13 of the ramjet combustor, the outlet of the diffuser is connected to the combustion section 14 of the ramjet combustor, and the divergence angle of the diffuser 3 is 7 ° to 9 °.

In the present embodiment, as shown in fig. 1, the front grille 1 is located at the inlet of the diffuser 3, and the outer annular edge 22 of the front grille is connected with the annular edge of the inlet of the diffuser 3. The grid is an annular conical surface grid, the conical angle of the profile of the grid is 90 degrees, the thickness of the grid is 5mm, and the projection width of the grid ring in the axial direction of the diffuser is 80 mm. Three rows of front grating holes 6 are arranged on the front grating, the opening direction of the front grating holes is backward along the central circumference of the diffuser, and the aperture of the front grating holes 6 is 30 mm. The three rows of front grille holes are distributed in an annular manner, the gap 17 between the three rows of holes is 2mm, and the gap 23 between the holes in each row is 2 mm. The outermost layer of front grating holes are half holes 18, the circle center of each half hole is a front grating outer ring 22, and the gap 19 between the innermost layer of grating holes and the inner ring edge 15 of the front grating is 1 mm.

In the present embodiment, as shown in fig. 1, the rear grid 2 is a reverse conical surface grid with a small radius, the radius 16 of the rear grid is 1 time of the radius of the inner annular edge 15 of the front grid minus the aperture of the grid by 30mm, the conical angle of the grid profile is 150 °, the thickness of the grid is 5mm, and the top of the reverse conical surface is a spherical surface 20 of SR 250.

In this embodiment, the opening direction of the rear grille holes 9 is backward along the diffuser center circumference, the grille holes have a diameter of 30mm, the grille holes are arranged in a 60-degree crossed manner, the gaps 24 between the grille holes are 4.1mm, and the grille holes crossed with the edge of the rear grille are treated as half holes 21.

In this embodiment, the diffuser inlet central area 5 is low-speed airflow, when the high-speed area airflow enters the diffuser 2 through the front grille 1, most of the airflow flows to the diffuser center along the profile of the front grille due to the blocking effect of the front grille 1, and a small part of the airflow passes through the grille holes 6 of the front grille and is decelerated to become low-speed airflow to continue flowing backwards along the diffuser edge area 7. When the buffered high-speed airflow 8 flowing to the center area of the diffuser under the action of the front grating 1 moves to the outlet of the diffuser 3 and passes through the rear grating 2, part of the airflow is decelerated into low-speed airflow through grating holes 9 of the rear grating and reaches more uniform distribution in the central area 10 of the inlet of the stamping combustion chamber, and the rest of the airflow 11 is scattered along the shape surface of the rear grating and around under the blocking action of the rear grating 2 and reaches more uniform distribution in the peripheral edge area 12 of the stamping combustion chamber. Through the combined rectification action of the front and the rear grids, the uneven airflow at the inlet can achieve a better rectification effect.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present disclosure should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a punching press combustion chamber rectification grid which characterized in that: comprises a front grating and a rear grating; the front grille is arranged at a diffuser inlet of the stamping combustion chamber and used for buffering high-speed airflow at the diffuser inlet and guiding part of the buffered high-speed airflow to the central area of the diffuser;

2. The stamped combustor fairing grid of claim 1, wherein: the front grating is in a circular truncated cone curved surface shape, the radius of the bottom is equal to the radius of the inlet of the diffuser, and the radius of the top is 0.7-0.8 times of the radius of the bottom; the front grille is fixed at the inlet of the diffuser through the bottom of the front grille.

3. The stamped combustor fairing grid as recited in claim 2, wherein: the grille holes in the front grille are uniformly distributed and are circular grille holes, and the radius of the grille holes is 0.08-0.09 time of the radius of the bottom of the front grille.

4. The stamped combustor fairing grid as recited in claim 2, wherein: the axial distance between the bottom of the front grating and the top of the front grating is 0.2-0.3 times of the radius of the bottom of the front grating.

5. The stamped combustor fairing grid of claim 1, wherein: the top of the rear grating is spherical, the main body of the rear grating is a circular truncated cone curved surface, the top of the rear grating faces the front grating, and the radius of the bottom of the rear grating is larger than that of the top of the front grating; the rear grating and the front grating are coaxially arranged.

6. The stamped combustor flow straightener grid of claim 3 or 5, wherein: the grid holes on the rear grid are uniformly distributed and are circular grid holes; the radius of the circular grid holes is equal to that of the grid holes of the front grid.

7. The stamped combustor fairing grid of claim 5, wherein: the axial distance between the bottom of the rear grating and the top of the rear grating is 0.2-0.3 times of the radius of the bottom of the rear grating.

8. The stamped combustor fairing grid of claim 5, wherein: the radius of the top spherical surface of the rear grating is 0.4-0.6 times of the radius of the bottom spherical surface of the rear grating.